191388420 has 240 divisors, whose sum is σ = 642690048. Its totient is φ = 47589120.

The previous prime is 191388419. The next prime is 191388473. The reversal of 191388420 is 24883191.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 1858089 + ... + 1858191.

Almost surely, 2^191388420 is an apocalyptic number.

191388420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 191388420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (321345024).

191388420 is an abundant number, since it is smaller than the sum of its proper divisors (451301628).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

191388420 is a wasteful number, since it uses less digits than its factorization.

191388420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 192 (or 181 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 191388420 is about 13834.3203663931. The cubic root of 191388420 is about 576.2866411861.

The spelling of 191388420 in words is "one hundred ninety-one million, three hundred eighty-eight thousand, four hundred twenty".